Not doing anything bad or inappropriate – just smiling, looking calm and wise, dressed in suitable clothes for a seventh-century Middle Eastern merchant. But a picture of the Prophet Mohammed. In colour. You know, to show what he looks like.

Unfortunately, if the experience of the makers of South Park is anything to go by, I would be profoundly unwise to do that. An Islamist group, Revolution Muslim, sent death threats to the show's makers at Comedy Central, saying that the producers would "probably wind up like Theo Van Gogh", the Dutch film-maker who was killed in 2004 for making a reportedly anti-Islamic movie. They included an photo of Mr Van Gogh's corpse with the message, in case anyone didn't get the point.

This is hardly an isolated example. We all remember the Salman Rushdie fatwa; the author of the webcomic Jesus and Mo has been subject to death threats*; and those Danish cartoons inspired global rioting. Interestingly, it seems that of all the cartoons, the images that sparked the most outrage (including one apparently showing Mohammed with a pig's snout but really of a French comedian in a pig-squealing contest) were added by Danish imams, apparently deliberately to stoke the fires.

Of course, if people are offended by the depiction of Mohammed, then – my opening paragraphs notwithstanding – as a rule, it's not a nice thing to do to offend people. But South Park makes a living out of offending people of all stripes, and not gratuitously – it does it (usually) to make a point. Jesus Christ has not been spared, nor Vishnu, nor Joseph Smith (Mormonism, in case you were wondering). I fail to see why Islam should get the soft soap. If Muslims don't like the show, they needn't watch it.

Now – to forestall accusations of Islamophobia – I should say I'm not Christianity's biggest fan. I don't like the prevailing attitude towards gay people; I think the business with condoms in Africa is unconscionable; I think parts of it are anti-scientific. It's not blameless on the (attempted) censorship front either – witness the pitiable Stephen Green of Christian Voice, hysterically picketing the BBC over Jerry Springer: The Opera, or reporting the atheist bus adverts to the Advertising Standards Agency. But I will say this for him: to my knowledge, he has never threatened to murder anyone for not being sufficiently nice about God. And, in the main, with some inglorious exceptions, neither do other Christians.

Like Christianity, Islam is based on the teachings of millennia-old holy books. Both are filled with some wonderful poetry and some powerful moral codes, and both – and I hope the Christians reading this will agree – have parts that simply have not stood the test of time.

Christianity, by and large, has moved with the zeitgeist, treating the Bible as metaphor where needs be (especially Genesis), and jettisoning much of the ethical teachings of the Old Testament, notably the weirder bits of Leviticus. Islam has yet to do a similar clear-out. It might be harder to achieve, since it is an article of the Islamic faith that the Koran is the inerrant word of God, whereas the Bible is more usually said to have been divinely inspired but humanly translated, leaving the possibility of error.

Whatever the reason, though, it is the case that people are scared of offending Islam. Interestingly, that was the point of the South Park episode – it was saying that only Islam can't "get ripped on", be mocked, take its punishment in the battleground of ideas like every other meme. And why is that? Because if you mock it, some of its believers – a tiny percentage, but a tiny percentage of a billion or so is still a large number – will threaten to hurt or kill you. That is not acceptable. It is bullying on a grand scale.

What we should do to bullies, we are told, is stand up to them. I wish I had the guts to do it here and print a picture. I don't, I'm sorry to say. But maybe if everyone did, all at once, we would start to make this bloody-yet-childish campaign to Stop Saying Mean Things Or I Will Kill You lose its force. And then, maybe the Islamic world would be less frightening to the West. Or maybe I'm being naive.

I imagine that some of the readers of this blog will think I've been unfair to Christianity here, and maybe I have. I imagine one or two of them will call me names. They are welcome to. That's pretty much my whole point.

Update: I initially wrote that the creator of Jesus and Mo had been subject to "thousands" of death threats. The author has got in touch to say that he can probably count the number of death threats on one hand. Apologies for the hyperbole.